12 Common Dog Diseases Every Dog Owner Should Know About
Every dog owner should be aware of the 12 most common diseases in dogs. Some of them are deadly, while others can be treated if caught early. This list does not include the more serious diseases such as cancer-diabetes etc. By being familiar with the symptoms and treatment options for each disease, you can help keep your dog healthy and happy. Read on to learn more about these common dog diseases every dog owner should know about.
1. Heartworm in Dogs: Symptoms, Prevention, and Treatment
Heartworms are parasitic worms that live in a dog’s heart and lungs, transmitted only through infected mosquito bites—not directly between dogs. Once inside, the larvae mature in 6-7 months, growing up to 12 inches long and clogging vital organs. Severe infections can lead to fatigue, coughing, weight loss, or even life-threatening Caval syndrome.
Prevention is key—monthly preventive medications (though not 100% foolproof) and annual testing are essential. If infected, treatment involves a series of injections (melarsomin) and strict rest to avoid complications. The process is costly and risky, making prevention far safer and more effective.
Heartworm Timeline After a Dog Is Bitten
- Day 0: Mosquito bites the dog, depositing microscopic heartworm larvae (microfilariae) into the bloodstream.
- Days 30–90: Larvae migrate through tissues, developing into immature worms.
- Months 3–4: Young worms enter blood vessels, moving toward the heart and lungs.
- Months 5–6: Worms mature into adults (up to 12 inches long) and begin reproducing.
- Month 6+: New microfilariae circulate in the blood, ready to infect another mosquito. Untreated, worms can live 5–7 years, causing severe damage to the heart and lungs.
Key Takeaway: It takes about 6 months for heartworms to become detectable on tests, which is why annual screening is crucial—even for dogs on prevention.
The importance of keeping a dog on heartworm prevention medication cannot be overstated-it is critical!
More great information can be found at the American Heartworm Society Website.
2. Intestinal Worms in Dogs: Causes, Symptoms, and How to Treat Them
There are several types of intestinal worms, including roundworms, hookworms, whipworms, and tapeworms, that cause health problems in dogs. Intestinal parasites are a very common disease in dogs. We are going to take a brief look at four of them: roundworms, hookworms, whipworms, and tapeworms. Generally, a fecal exam is needed to detect intestinal parasites as most worms are not detectable to the naked eye.
Roundworms
Roundworms may be transmitted to a mother to their puppies during birth or even from the nursing mothers milk. Female roundworms can produce up to 100,000 eggs in one day. The eggs are encased in a hard shell and can last in soil for several years! When eaten by a dog, the larvae hatch and grow in the intestines. A severe roundworm infection can cause death. Fortunately, they are many dewormers available to treat this parasite.
Hookworms
Hookworms are slender worms with a hook-like mouth that attaches inside the intestines of its host. These tiny worms can only be detected under a microscope. A severe infestation can kill puppies. Hookworm larvae is passed to puppies through their mother’s milk. Contact with feces-contaminated soil also spreads this parasite as the larvae can burrow through the skin of a dogs paws. Hookworms are treated by administering a dewormer medication.
Whipworms
Whipworms live in a dog’s large intestine and are very difficult to detect. A dog becomes infected with this parasite by ingesting soil, grass, feces etc. that is contaminated. Whipworms look like tiny pieces of thread! These worms intermittently shed eggs in a dogs’ stool which can survive for years. A dog with whipworms may have a negative stool sample one week and positive the next!
Most dogs develop few symptoms, making this parasite even harder to detect. Fortunately, this is not a life-threatening condition and can be treated with medication.
Tapeworms
Tapeworms are a long, segmented worm that is carried by fleas. These worms live in a dogs intestines and can reach 1-2 feet in length! Most dogs do not become sick but you may notice them scooting across the floor and an irritation around the anus. You may see tiny “rice-like” grains around their hind-side. Tapeworms can generally be treated with over the counter medications specifically labeled to treat them.
Prevalence of Common Canine Intestinal Worms
- Roundworms (Toxocara canis):
- Most common intestinal parasite in dogs, especially puppies.
- Prevalence: Found in 5–30% of dogs (higher in puppies and stray/rescue populations).
- Hookworms (Ancylostoma caninum):
- More common in warm, humid climates.
- Prevalence: Affects 2–20% of dogs (can be fatal in puppies due to blood loss).
- Whipworms (Trichuris vulpis):
- Harder to detect due to intermittent egg shedding.
- Prevalence: Found in 1–15% of dogs (higher in kennels or densely populated areas).
- Tapeworms (Dipylidium caninum from fleas; Taenia spp. from prey*):
- Very common in dogs with flea infestations or hunting/scavenging habits.
- Prevalence: Up to 10–15% of dogs (fleas are the #1 cause).
Key Takeaways
- Puppies & strays are at highest risk due to maternal transmission and poor sanitation.
- Flea control is critical to preventing tapeworms.
- Regular fecal tests (at least 1–2x/year) are recommended—many infections show no obvious symptoms early on.
Sources: CAPC (Companion Animal Parasite Council), AAHA, and peer-reviewed veterinary studies
More information of treating worms in dogs-including natural methods can be found at Dogs Naturally.
3. Parainfluenza in Dogs: Prevention & Care
Canine parainfluenza – a highly contagious respiratory virus – affects an estimated 20-30% of dogs in high-risk environments like shelters and kennels annually (source: Merck Veterinary Manual). Spread through direct contact, contaminated items, or airborne particles, it causes coughing, fever, nasal discharge, and lethargy. While antibiotics may treat secondary infections, prevention is key: the DHPP vaccine (which includes parainfluenza protection) and minimizing exposure in crowded areas are essential. Diagnosis typically requires a blood test or PCR, but isolating infected dogs remains crucial to control outbreaks.
4. Kennel Cough in Dogs: Causes & Care
Kennel cough (canine infectious respiratory disease) affects nearly 1 in 10 dogs annually (source: AVMA), with Bordetella bronchiseptica being the most common bacterial cause. Spread through airborne droplets or contaminated items, it triggers a hacking cough, sneezing, and mild fever. While most cases resolve in 2–3 weeks, severe infections can lead to pneumonia. Treatment includes rest and antibiotics, but prevention is best: the Bordetella vaccine (often required for boarding) reduces risk, especially in high-traffic areas like dog parks or kennels.
Here are some potential home remedies for kennel cough in dogs.
5. Leptospirosis in Dogs: Risks & Prevention
Leptospirosis, a deadly bacterial infection spread through contaminated water or contact with infected animals (rodents, wildlife, livestock), affects about 1 in 10 unvaccinated dogs (source: WSAVA). The bacteria attack kidneys and liver, causing vomiting (sometimes bloody), fever, and dehydration. While 25% of dogs may recover naturally, severe cases lead to irreversible organ damage. Diagnosis requires specialized tests (PCR/MAT), and treatment involves aggressive antibiotics. Prevention includes vaccination (though not 100% effective) and avoiding stagnant water. Note: This zoonotic disease can spread to humans—wear gloves when handling infected dogs.
6. Giardiasis in Dogs: Symptoms & Prevention
Giardia is an intestinal parasite that infects dogs when they ingest contaminated water, soil, or feces containing hardy Giardia cysts. These cysts thrive in damp environments for months, making puddles, lakes, and even grass potential sources. Symptoms include diarrhea (often with mucus), vomiting, gas, and weight loss. Treatment typically involves antibiotics like fenbendazole.
While there’s no preventive medication, minimizing exposure is key: avoid stagnant water, clean up feces promptly, and practice good hygiene (though human transmission is rare). Regular deworming and clean living spaces help reduce risks.
Giardia affects ~10-15% of dogs (CAPC), especially in crowded or outdoor environments.
7. Canine Distemper: Symptoms & Prevention
Canine distemper is a deadly, highly contagious virus spread through direct contact or airborne droplets, attacking a dog’s respiratory, nervous, and digestive systems. Symptoms include fever, coughing, vomiting, lethargy, and hardened paw pads (“hard pad disease”). While survival is possible, survivors often face lifelong neurological issues like seizures.
Prevention is critical—vaccination is highly effective. Puppies and unvaccinated dogs are most at risk, with fatality rates up to 50% in adults and 80% in puppies (AVMA). Keep your dog’s shots current to avoid this devastating disease.
Note: Distemper also threatens ferrets and wildlife like raccoons.
8. Canine Hepatitis: Causes & Care
Canine hepatitis, a serious liver inflammation, stems from toxins, infections (like adenovirus), or genetic factors—with breeds like Dalmatians and Dobermans prone to copper-related cases. Symptoms include lethargy, vomiting, excessive thirst, and appetite loss.
Diagnosis requires blood tests, urinalysis, and ultrasounds. While incurable, management with steroids, liver-support drugs (UDCA), and a low-copper diet can help. Prevention tip: Check dog food labels for excessive copper additives.
Note: Infectious hepatitis (from adenovirus) is preventable via vaccination.
9. Lyme Disease in Dogs: Recognizing Symptoms and Preventing Ticks
Lyme disease, caused by Borrelia burgdorferi bacteria transmitted through deer tick bites, often shows no symptoms (affecting less than 10% of infected dogs). When signs appear (3–5 months post-bite), they include fever, joint stiffness, lethargy, and appetite loss. Severe cases can lead to kidney failure or heart issues.
Diagnosis & Treatment:
- Blood tests (C6 antibody test) confirm infection.
- Symptomatic dogs receive 4–8 weeks of antibiotics; asymptomatic dogs typically don’t need treatment.
Prevention is key: Use vet-recommended tick preventatives year-round and check your dog after outdoor activities. Note: Lyme can’t spread from dogs to humans—but shared environments (like wooded areas) raise risk for both.
10. Rabies in Dogs: A Deadly But Preventable Threat
Rabies is a fatal viral disease transmitted through bites from infected animals like raccoons, bats, and foxes. The virus attacks the nervous system, leading to two forms: “dumb rabies” (paralysis, drooling) or “furious rabies” (aggression, seizures). Once symptoms appear (typically within 14 days to 3 months), death is nearly certain.
Key Facts:
- 100% preventable with routine vaccination (required by law in most areas).
- If a vaccinated dog is bitten, a booster shot and 14-day quarantine may be required.
- No cure exists for unvaccinated dogs—euthanasia is the only option.
Protect Your Pet: Keep rabies vaccines current and avoid contact with wildlife. Remember: Rabies is zoonotic—humans can catch it too.
You can read more on “How to Prevent Rabies in Dogs”.
Clicking the above map will take you to rabiesaware.org where you can check state by state laws for rabies requirements.
11. Parvovirus in Dogs: A Deadly Threat with Hope Through Prevention
Parvovirus is a highly contagious, often fatal disease that attacks a dog’s intestines and immune system. Spread through contact with infected feces or contaminated objects (where the virus can survive for months), it causes severe vomiting, bloody diarrhea, lethargy, and dehydration. Puppies and unvaccinated dogs are most at risk, with mortality rates exceeding 70% without treatment.
Key Facts:
- No cure exists, but hospitalization (IV fluids, antibiotics) boosts survival to 68–92% (Merck Veterinary Manual).
- Certain breeds (Rottweilers, German Shepherds, Labs) are more susceptible—but vaccination is critical for all dogs.
- Prevention is paramount: The parvo vaccine is highly effective, and bleach is the only common disinfectant proven to kill the virus.
Act Fast: If you suspect parvo, seek emergency vet care immediately—every hour counts.
Remember: While parvo can’t infect humans, you can unwittingly spread it to other dogs—quarantine and disinfect thoroughly.
Source:canineparvovirus.org
12. Canine Coronavirus (CCV): What Dog Owners Should Know
Canine coronavirus (CCV) is a highly contagious intestinal infection spread through contact with infected feces or contaminated objects. Unlike COVID-19, CCV does not affect humans and typically causes mild or no symptoms—though puppies may face severe diarrhea and dehydration.
Key Facts:
- Symptoms (if any): Diarrhea, fever, lethargy (appears 4–7 days post-exposure).
- Recovery: Most adult dogs clear the virus naturally; puppies may need supportive care (fluids, antibiotics for secondary infections).
- Vaccine available, but not routinely recommended—consult your vet based on risk factors.
Prevention Tip: Practice good hygiene (prompt poop cleanup, disinfect bowls/areas) to reduce spread.
When to Worry: If diarrhea persists >24 hours or a puppy shows signs of dehydration (sunken eyes, dry gums), seek veterinary care.
FAQ – Common Canine Illnesses
1. What Are the Most Common Vaccines for Dogs?
Core vaccines include rabies, distemper, parvovirus, and adenovirus (canine hepatitis). Puppies need a series of shots, followed by boosters every 1–3 years (per your vet’s advice).
2. Can Dogs Survive Parvovirus Without Treatment?
Not Likely—untreated parvo has a 70%+ fatality rate. With hospitalization (IV fluids, antibiotics), survival chances jump to 68–92%. Immediate vet care is critical.
How can I protect my dog from intestinal worms?
Regular deworming is crucial to prevent and control intestinal worms. Speak to your veterinarian about the appropriate deworming schedule for your dog, based on their age, lifestyle, and risk factors.
What are the symptoms of kennel cough?
Kennel cough typically presents as a dry, hacking cough, sneezing, nasal discharge, and sometimes lethargy or loss of appetite. If you suspect your dog has kennel cough, consult with your vet for proper diagnosis and treatment.
Is leptospirosis contagious to humans?
Yes, leptospirosis is a zoonotic disease that can be transmitted from animals to humans through contact with infected urine or contaminated water sources. Vaccination and proper hygiene practices are important for preventing transmission.
12 Common Dog Diseases – Key Takeaways for Pet Owners
As responsible dog owners, recognizing the most common dog diseases—from parvovirus to Lyme disease—is the first step in protecting your pet’s health. Early detection, preventive care (like core vaccinations), and prompt veterinary attention can mean the difference between a treatable condition and a life-threatening emergency.
Remember:
✔ Vaccinate against preventable diseases (rabies, distemper, parvo)
✔ Monitor for symptoms (lethargy, appetite changes, diarrhea)
✔ Prevent exposure (flea/tick control, clean environments)
By staying informed and proactive, you’re giving your dog the best chance at a long, healthy life—filled with more tail wags and fewer vet visits. When in doubt, always consult your veterinarian—they’re your partner in your pet’s lifelong wellness journey.
Want to know which dog breeds are effected by diseases such as cancer, Arthritis, Heart Disease etc?
The Most Serious Canine Diseases and the Dog Breeds they Effect Most
